With the Dow hitting new highs, retail investors are surging back into stocks That's good news for TD Ameritrade. Pushing wealth management for the mass-affluent. Why the stock could rise 30%.

The retail investor is finally back in the stock market, which is good news for TD Ameritrade Holding (ticker: AMTD), the country's largest online broker by retail trading volumes. Over the past decade, the Omaha, Neb.–based firm, which once catered strictly to active traders, has expanded its focus to longer-term, mass-affluent investors and registered investment advisors. Ameritrade describes the mass affluent as those with $100,000 to $750,000 in investible assets.